Iran "condemns the brutal US military aggression against Iran's peaceful nuclear facilities" and reserves the right to defend itself with full force, said an official statement by the Iranian Foreign Ministry on Sunday.

The US military assault on Iran's peaceful nuclear facilities is not only a blatant and unprecedented violation of the UN Charter -- particularly the principles prohibiting the use of force and requiring respect for states' territorial integrity and national sovereignty-- but also a violation of UN Security Council Resolution 2231, the statement said.

"The world must not forget that it was the United States that, in the midst of a diplomatic process, betrayed diplomacy by supporting the genocidal and lawbreaking Israeli regime to impose a war of aggression on the Iranian nation. Now, in completion of that regime's unlawful and criminal acts, the United States itself has launched a dangerous war against the Islamic Republic of Iran," said the statement released on X platform.

Iran "is resolved to defend Iran's territory, sovereignty, security and people by all force and means against the United States' criminal aggression," said the statement.

At a news conference earlier, US President Donald Trump said Saturday local time that Iran's key nuclear facilities had been "completely and totally obliterated". US military struck Iran's atomic energy sites at Fordow, Natanz and Isfahan. But Iran had evacuated these three nuclear sites "a while ago," said Hassan Abedini, deputy political director of Iran's state broadcaster.

Trump also threatened that future attacks against Iranian targets will be "far greater and a lot easier". "If peace does not come quickly, we will go after those other targets with precision, speed and skill," he said at his news conference.

The Iranian Foreign Ministry also urged the UN Security Council to convene an emergency session to "unequivocally condemn this criminal act of aggression by the United States against Iran" and to hold the United States accountable for its egregious violation of the fundamental principles of United Nations Charter and of the norms of international law.

The ministry also called on the IAEA Board of Governors to immediately convene and "carry out its legal responsibility in response to this dangerous US attack on Iran's peaceful nuclear facilities, all of which have been under the Agency's full safeguards and monitoring."

The "war-mongering and lawless regime of the United States of America" is held fully responsible for the dangerous consequences and far-reaching implications of this egregious act of aggression and heinous crime, the ministry said.

Jan Yumul contributed to this report.